Medical Skin Mountable Device and System

ABSTRACT

A medical device is provided comprising a transcutaneous device unit and a process unit. The transcutaneous device unit may comprise a transcutaneous device for transporting a fluid through a skin portion of a subject, and a mounting surface adapted for application to the skin of the subject. The process unit may comprise a reservoir adapted to contain a fluid drug, the reservoir comprising an outlet means allowing the transcutaneous device to be arranged in fluid communication with an interior of the reservoir, and an expelling assembly for expelling a fluid drug out of the reservoir and through the skin of the subject via the transcutaneous device. The transcutaneous device unit and the process unit further comprise coupling means allowing the reservoir unit to be secured to the transcutaneous device unit in the situation of use. By this arrangement a two-unit system is provided which can be used in a convenient and cost-effective manner.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.11/911,213 filed Oct. 11, 2007, which is a 35 U.S.C. §371 national stageapplication of International Patent Application PCT/EP2006/061444(published as WO 2006/108809), filed Apr. 7, 2006, which claimedpriority of Danish Patent Application PA 2005 00526, filed Apr. 13,2005; this application further claims priority under 35 U.S.C. §119 ofU.S. Provisional Application 60/670,754, filed Apr. 13, 2005,incorporated by reference in their entirety as if fully set forthherein.

The present invention generally relates to devices which are adapted forapplication to a skin surface of a subject and comprise a transcutaneousdevice which can be used for e.g. introduction of a fluid through theskin of the subject or as a sensor. In specific aspects, such devicesmay comprise a reservoir adapted to contain a fluid drug, and expellingmeans for expelling fluid drug out of the reservoir and through the skinof the subject via the transcutaneous device.

BACKGROUND OF THE INVENTION

In the disclosure of the present invention reference is mostly made tothe treatment of diabetes by injection or infusion of insulin, however,this is only an exemplary use of the present invention.

Portable drug delivery devices for delivering a drug to a patient arewell known and generally comprise a reservoir adapted to contain aliquid drug and having an outlet in fluid communication with a hollowinfusion needle, as well as expelling means for expelling a drug out ofthe reservoir and through the skin of the subject via the hollow needle.Such devices are often termed infusion pumps.

Basically, infusion pumps can be divided into two classes. The firstclass comprises infusion pumps which are relatively expensive pumpsintended for 3-4 years use, for which reason the initial cost for such apump often is a barrier to this type of therapy. Although more complexthan traditional syringes and pens, the pump offer the advantages ofcontinuous infusion of insulin, precision in dosing and optionallyprogrammable delivery profiles and user actuated bolus infusions inconnections with meals.

Addressing the above problem, several attempts have been made to providea second class of drug infusion devices that are low in cost andconvenient to use. Some of these devices are intended to be partially orentirely disposable and may provide many of the advantages associatedwith an infusion pump without the attendant cost and inconveniencies,e.g. the pump may be prefilled thus avoiding the need for filling orrefilling a drug reservoir. Examples of this type of infusion devicesare known from U.S. Pat. Nos. 4,340,048 and 4,552,561 (based on osmoticpumps), U.S. Pat. No. 5,858,001 (based on a piston pump), U.S. Pat. No.6,280,148 (based on a membrane pump), U.S. Pat. No. 5,957,895 (based ona flow restrictor pump (also know as a bleeding hole pump)), U.S. Pat.No. 5,527,288 (based on a gas generating pump), or U.S. Pat. No.5,814,020 (based on a swellable gel) which all in the last decades havebeen proposed for use in inexpensive, primarily disposable drug infusiondevices, the cited documents being incorporated by reference. U.S. Pat.No. 6,364,865 discloses a manually held infusion device allowing twovial-type containers to be connected and a pressure to be build up inone of the containers to thereby expel a drug contained in thatcontainer.

The disposable pumps generally comprises a skin-contacting mountingsurface adapted for application to the skin of a subject by adhesivemeans, and with the infusion needle arranged such that in a situation ofuse it projects from the mounting surface to thereby penetrate the skinof the subject, whereby the place where the needle penetrates the skinis covered while the appliance is in use. The infusion needle may bearranged to permanently project from the mounting surface such that theneedle is inserted simultaneously with the application of the infusionpump, this as disclosed in U.S. Pat. Nos. 2,605,765, 4,340,048 and in EP1 177 802, or the needle may be supplied with the device in a retractedstate, i.e. with the distal pointed end of the needle “hidden” insidethe pump device, this allowing the user to place the pump device on theskin without the possibility of observing the needle, this as disclosedin U.S. Pat. Nos. 5,858,001 and 5,814,020. In addition to pumps,alternative means for transporting a fluid drug may be used, e.g.iontophoresis as discussed below.

Although it can be expected that the above described second class offully or partly disposable infusion devices can be manufacturedconsiderably cheaper than the traditional durable infusion pump, theyare still believed to be too expensive to be used as a real alternativeto traditional infusion pumps for use on an every-day basis.

Before turning to the disclosure of the present invention, a differenttype of device relying on the insertion of a needle or needle-likestructure will be described.

Although drug infusion pumps, either disposable or durable, may provideconvenience of use and improved treatment control, it has long been anobject to provide a drug infusion system for the treatment of e.g.diabetes which would rely on closed loop control, i.e. being more orless fully automatic, such a system being based on the measurement of avalue indicative of the condition treated, e.g. the blood glucose levelin case of insulin treatment of diabetes.

A given monitor system for measuring the concentration of a givensubstance may be based on invasive or non-invasive measuring principles.An example of the latter would be a non-invasive glucose monitorarranged on the skin surface of a patient and using near-IRspectroscopy, however, the present invention is concerned primarily withdevices comprising a transcutaneous device such as a needle-formedsensor element.

The sensor may be placed subcutaneously being connected to externalequipment by wiring or the substance (e.g. fluid) to be analysed may betransported to an external sensor element, both arrangements requiringthe placement of a subcutaneous component (e.g. small catheter ortubing), the present invention addressing both arrangements. However,for simplicity the term “sensor” is used in the following for both typesof elements introduced into the subject.

DISCLOSURE OF THE INVENTION

Having regard to the above-identified problems, it is an object of thepresent invention to provide a skin mountable drug delivery device orsystem and components therefore, which allow such a device or system tobe used in a convenient and cost-effective manner. The configuration ofthe system and the components therefore should contribute in providing amedical delivery means which allows for easy and swift operation yetbeing reliable in use.

In the disclosure of the present invention, embodiments and aspects willbe described which will address one or more of the above objects orwhich will address objects apparent from the below disclosure as well asfrom the description of exemplary embodiments.

Thus, corresponding to a first aspect, a medical device comprising atranscutaneous unit and a process unit is provided, wherein thetranscutaneous device unit comprises a mounting surface adapted forapplication to the skin of the subject, and a transcutaneous devicecomprising a distal end adapted to be inserted through the skin of asubject, the distal end being movable between an initial position inwhich the distal end is retracted relative to the mounting surface, andan extended position in which the distal end projects relative to themounting surface, and wherein the process unit comprises a processassembly adapted to cooperate with the transcutaneous device, whereinthe transcutaneous device unit and the process unit are adapted to besecured to each other to form a unitary device. By the term “unitary” isindicated that the two units are not merely physically connected by somekind of “loose” structure such as a flexible wire or a flexible fluidconduit as when connecting a conventional infusion set to a conventionalinfusion pump.

When it is defined that the two units are adapted to be secured to eachother, this also covers the situation in which a portion of thetranscutaneous device unit has to be removed prior to securing theprocess unit. This may e.g. be the case where the transcutaneous deviceunit comprises a removable inserter portion.

The transcutaneous device unit may be provided with actuation means formoving the distal end of the transcutaneous device between the initialand the extended position when the actuation means is actuated.

The term “process assembly” covers an aggregation of components whichare adapted to interact with the transcutaneous device to provide agiven functionality. For example, the transcutaneous device may be inthe form of a transcutaneous sensor device, and the process assemblycomprises a processor adapted to transmit and/or process data acquiredvia the sensor device.

In another example, the transcutaneous device is in the form of atranscutaneous access device, and the process assembly comprises areservoir adapted to contain a fluid drug, an expelling assembly adaptedfor cooperation with the reservoir to expel fluid drug out of thereservoir and through the skin of the subject via the transcutaneousaccess device, and a processor for controlling the expelling assembly. Atranscutaneous device may also be combined with a sensor element to forma combined transcutaneous device. Such a medical device may be used in asystem further comprising a remote control unit comprising a processor,the medical device and the remote control unit being adapted to transmitdata therebetween. The remote control unit may be adapted to receiveexternally supplied values and calculate a bolus amount of drug to beinfused based upon the externally supplied values, e.g. it may beadapted to calculate a bolus amount of drug to be infused based uponexternally supplied values representing material to be ingested by thebody of the subject. The system may comprise a first analyte sensordevice adapted to provide data indicative of a concentration of thefirst analyte in the user, the remote control unit comprising aninfusion calculator for calculating a bolus or infusion rate on thebasis of data supplied by the first analyte sensor. The system may alsocomprise a second analyte sensor device adapted to provide dataindicative of a concentration of the second analyte in the user, theremote control unit comprising an infusion calculator for calculating abolus or infusion rate on the basis of data supplied by the first andsecond analyte sensors. The first and second analytes may be bloodglucose, in which case the first analyte sensor is a BGM, the secondanalyte sensor is a CGM, and the remote control unit is adapted tocalculate an amount or infusion rate of insulin.

For the different embodiments described above, the medical device orsystem may comprise releasable mating coupling means for securing thetranscutaneous device unit and the process unit to each other to form asubstantially rigid connection therebetween.

In a further aspect a system is provided comprising a firsttranscutaneous device unit and a first process unit as described above,and at least one further transcutaneous device unit being different fromthe first transcutaneous device unit, whereby each combination of atranscutaneous device unit and a process unit provides differentcapabilities. Alternatively, a system is provided comprising a firsttranscutaneous device unit and a first process unit as described above,and at least one further process unit being different from the firstprocess unit, whereby each combination of a transcutaneous device unitand a process unit provides different capabilities.

The term “capabilities” is used to denote a set of actions or functionsresulting from a combination of the two units. The differentcapabilities may be based on structure (e.g. different patch unitshaving different transcutaneous devices) or functionality (e.g.different pump units being programmed to deliver at different infusionrates). In the context of the present application, the term “differentcapabilities” is also used to indicate that the “potential” capabilitiesare different, however, in case the capabilities are overlapping, theuser may e.g. choose to operate a given pump unit corresponding to thecapabilities of another pump unit, or two different pump units may beused in the same way. For example, a pump unit allowing user-programmingof infusion profiles as well as a bolus function may be used to activatea simple constant flow rate corresponding to the capabilities of asimple pump unit.

The present invention also provides a method of using the componentscomprising the steps of (i) providing a transcutaneous device unitcomprising a transcutaneous device and a mounting surface, thetranscutaneous device having retracted position relative to the mountingsurface, and an extended position in which a distal end projectsrelative to the mounting surface, (ii) providing a process unitcomprising a process assembly adapted to cooperate with thetranscutaneous device, (iii) mounting the mounting surface to a skinsurface of a subject, (iv) inserting the transcutaneous device into thesubject by moving the transcutaneous device from the retracted positionto the extended position, and (v) assembling the transcutaneous deviceunit and the process unit to provide a functional communication betweenthe process assembly and the inserted transcutaneous device. Theinsertion step may take place after the assembling step, just as theinsertion may be automatically activated when the two units areassembled. Alternatively, the two units may be assembled before they aremounted to the skin surface and the transcutaneous device inserted.

Corresponding to a further aspect, a medical device comprising atranscutaneous unit and a reservoir unit is provided, wherein thetranscutaneous unit comprises transcutaneous means for transporting afluid through a skin portion of a subject, and a mounting surfaceadapted for application to the skin of the subject. The reservoir unitcomprises a reservoir adapted to contain a fluid drug, the reservoircomprising an outlet allowing the transcutaneous means to be arranged influid communication with an interior of the reservoir, and expellingmeans for, in a situation of use, expelling a fluid drug out of thereservoir and through the skin of the subject via the transcutaneousmeans. The transcutaneous unit and the reservoir unit further comprisecoupling means allowing the reservoir unit to be secured to thetranscutaneous unit in the situation of use.

The term “transcutaneous” covers all forms of administration in which afluid is transported through a portion of the skin, e.g. intradermal orsubcutaneous administration. The transcutaneous means may be in the formof a transcutaneous device, a jet injection means or electrodes allowingan ionic agent to permeate from a predetermined site on the surface ofskin into the subcutaneous tissue of the subject by using the principleof iontophoresis. For a more thorough discussion of iontophoresisreference is made to U.S. Pat. No. 6,622,037 hereby incorporated byreference. Depending on the nature of the transcutaneous means theexpelling means may be of different configuration and nature. Forexample, when one or more hollow infusion needles or cannulas are used,the expelling means may be arranged to force or suck the fluid drug fromthe reservoir, whereas in the case of iontophoresis the expelling meanswould be means for applying a current over a set of electrodes, i.e.“driving” means.

Corresponding to a further aspect, a medical device comprising atranscutaneous device unit and a reservoir unit is provided, wherein thetranscutaneous device unit comprises a transcutaneous device, and amounting surface for application to the skin of the subject. Thereservoir unit comprises a reservoir adapted to contain a fluid drug,and an expelling assembly adapted for cooperation with the reservoir toexpel the fluid drug out of the reservoir and through the skin of thesubject via the transcutaneous device. The transcutaneous device unitand the reservoir unit are further adapted to be secured to each otherin a situation of use thereby allowing a fluid communication to beestablished between the reservoir and the transcutaneous device. Thetranscutaneous device unit and the reservoir unit may comprisereleasable coupling means allowing the reservoir unit to be secured tothe transcutaneous device unit in a situation of us. Such a medicaldevice comprising two units may also be considered a medical system. Thetranscutaneous device unit and the reservoir unit may each comprise ahousing within which the transcutaneous device respectively thereservoir and the expelling assembly are arranged.

The term expelling assembly covers an aggregation of components orstructures which in combination provides that a fluid can be expelledfrom the reservoir. The expelling assembly may e.g. be a mechanical pump(e.g. a membrane pump, a piston pump or a roller pump) in combinationwith electronically controlled actuation means, a mechanically drivenpump (e.g. driven by a spring), a gas driven pump or a pump driven by anosmotic engine. The expelling assembly may also me in the form of anaggregation of components or structures which in combination providesthat a fluid can be expelled from the reservoir when the expellingassembly is controlled or actuated by a controller external to theexpelling assembly.

The transcutaneous device (which term also covers the similar termstranscutaneous access device and transcutaneous access tooltraditionally used in this technical field) may be in the form of apointed hollow infusion needle, a micro needle array, or a relativelyflexible per se blunt cannula (or sensor) may be provided in combinationwith a pointed insertion needle, the insertion needle being retractableafter insertion of the blunt portion of the transcutaneous device. Theterm “transcutaneous device” may also be used to denote such acombination although only a part of it is adapted to be inserted for anextended period of time. The cannula is advantageously soft and flexiblerelative to the insertion needle which typically is a solid steelneedle. Especially when the transcutaneous device is in the form of arigid needle it may be advantageous to provide retraction means for sucha needle. In the disclosure of the present invention as well as in thedescription of the exemplary embodiments, reference will mostly be madeto a transcutaneous device in the form of an infusion needle or cannula.The length of the transcutaneous device may be chosen in accordance withthe actual application, e.g. a hollow steel needle which may be insertedat a substantially right angle relative to the skin surface may have aninserted length of 2-8 mm, preferably 3-5 mm, whereas a cannula whichmay also be inserted at an oblique angle relative to the skin surfacemay be somewhat longer, e.g. 4-20 mm.

In an exemplary embodiment the insertion needle is a hollow needlearranged coaxially with and outside the transcutaneous device and beingaxially movable relative thereto, the needle comprising a distal portionadapted to penetrate the skin of the subject, wherein the medical deviceis transformable between (a) a first state in which the transcutaneousdevice and the needle are retracted relative to the mounting surface,(b) a second state in which the transcutaneous device and the needle areextended relative to the mounting surface with the distal end of theneedle projecting relative to the distal portion of the transcutaneousdevice thereby allowing the transcutaneous device to be introducedthrough the skin of the subject, and (c) a third state in which thedistal end of the needle is retracted relative to the distal portion ofthe transcutaneous device. The process unit may be adapted to bereleasably coupled to the transcutaneous device unit thereby, in asituation of use, substantially covering an introduction site of thetranscutaneous device through the skin, wherein at least partial removalof the process unit from the transcutaneous device unit at leastpartially uncovers the introduction site.

The mounting surface is adapted for application against the skin of asubject (e.g. user or patient) and may be held in contact with the skinby attaching means external to the mounting surface (e.g. coupling meansallowing the medical device to be coupled to a skin mountable device, oran adhesive bandage or a dressing) or by adhesive means provided on themounting surface. The mounting surface may also be adapted for mountingtowards the skin via an interposed component of a skin mountable device,e.g. a skin mountable device may comprise a receiving portion to whichthe medical device is attached, the transcutaneous device being insertedinto the skin through an aperture in the receiving portion.

By the above arrangement different concepts can be realized. Forexample, by providing at least two different of one of the units, itwill be possible to provided two or more combinations, wherein eachcombination of a transcutaneous device unit and a reservoir unitprovides an assembly will have different capabilities as discussed infurther detail below. In case the units are provided with releasablecoupling means, one of the units can be exchanged with a new ordifferent unit yet allowing the other unit to be re-used, therebylengthening the operational life of the re-used unit. Thus, the presentinvention provides in an exemplary embodiment a device in which thecomponents providing the interface with the user is incorporated in afirst unit whereas the components providing the drug delivery per se isincorporated in a second unit, this allowing the combined components tobe combined or exchanged in a simple, reliable and user-friendly way.

For example, the reservoir unit may be provided with an amount of drugand a delivery pump comprising an energy source allowing the drug to bedelivered over e.g. 10 days, whereas the transcutaneous device unit maybe provided with a transcutaneous device and an adhesive surface on themounting surface having an expected (or recommended) operational life of2 days, this allowing the reservoir unit to be used with 5transcutaneous device units over a period of 10 days, this considerablylowering the total costs of using the combined device. The reservoir maybe pre-filled or adapted to be filled one or more times.

On the other hand, a transcutaneous device unit may be provided withe.g. a needle or a soft cannula, and adhesive means (e.g. of the typeused for attaching colostomy bags) allowing the needle unit to bemounted and used over an extended period of time, the reservoir unithaving a shorter expected operational life, e.g. when relatively largeamounts of drugs have to be infused. Alternatively, different reservoirunits with different types of drugs may be used in combination with sucha “long-term” mounted needle unit.

For ease of use, the fluid communication between the needle and thereservoir may be established when the needle unit and the reservoir unitare secured to each other, just as the expelling means may be activatedwhen the needle unit and the reservoir unit are secured to each otherand de-activated when the units are released from each other. Indeed,one or both of the operations may also be performed manually by theuser.

In an exemplary embodiment the expelling assembly comprises a pumphaving an inlet adapted to be arranged in fluid communication with theoutlet of the reservoir, and an outlet adapted to be arranged in fluidcommunication with the transcutaneous device, thereby allowing thetranscutaneous device to be arranged in fluid communication with theinterior of the reservoir. By such an arrangement the pump will serve asa suction pump drawing drug from the reservoir which consequently willhave to be either collapsible or vented in case a non-collapsiblereservoir is used. The expelling assembly may also be in the form of anarrangement adapted to pressurize the reservoir, e.g. an arrangement fordriving a piston in a reservoir comprising a displaceable piston. Thereservoir unit may comprise more than one reservoir and more than oneexpelling assembly. For example, a single expelling assembly may be usedto expel drug from more than one reservoir, either simultaneouslythereby mixing drugs or alternating, or each reservoir may be providedwith an expelling assembly which may be connected to a commontranscutaneous device or to individual transcutaneous devices, e.g. thetranscutaneous device unit may comprise more than one transcutaneousdevice adapted to be connected to a expelling assembly.

In order to provide an initially sterile flow path through the pump, theflow path may be arranged between the inlet and outlet such that theinlet and outlet seal the interior of the pump and thereby the flow pathin an initial sterile state. By this arrangement it will not benecessary to provide the reservoir unit as an entirely sterile unitindeed, the drug will have to be provided in a sterile state.

In an exemplary embodiment, the reservoir unit is transformable from aninitial condition in which there is no fluid communication between thepump and the reservoir to a non-reversible operating condition in whichfluid communication is established between the inlet means of the pumpand the outlet means of the reservoir when the pump unit is secured to aneedle unit for the first time. By this arrangement it is avoided thatundesired matter is introduced into the reservoir during re-connectionbetween the pump and the reservoir.

To secure a clean connection between the pump and the reservoir, aseparate fluid connector may be arranged within the interior of the pumpin the initial condition. Such a fluid connector may comprise a pointedinlet end and an outlet, whereas the inlet of the pump and the outlet ofthe reservoir may be in the form of two needle-penetratable septa. Bythis arrangement the pointed end of the fluid connector, e.g. aconnection needle, can be moved through the two septa and thus betweenthe initial condition and an operating condition in which fluidcommunication is established between the interior of the reservoir andthe interior of the pump via the fluid connector, the outlet of thefluid connector being arranged in the flow path. Advantageously thefluid connector is moved between its two positions as the reservoir unitis connected to a transcutaneous device unit for the first time.Correspondingly, during such a first connection two fluid communicationswill be established (between the transcutaneous device of thetranscutaneous device and the pump, and between the pump and thereservoir), whereas during subsequent connections only a single newfluid communication will be established (between the transcutaneousdevice of the transcutaneous device unit and the pump).

In an exemplary embodiment the transcutaneous device comprises a firstportion having a pointed distal end, and a second portion in fluidcommunication with the first portion and having a second end.Advantageously the second end of the transcutaneous device is pointedand the outlet means of the pump comprises a needle-penetratable septumallowing a fluid communication to be established between the second endof the transcutaneous device and the interior of the pump, preferably asthe two units are connected to each other.

Correspondingly, in a further aspect the present invention provides apump having an inlet means adapted to be arranged in fluid communicationwith a fluid supply, and an outlet means, the pump comprising aninternal flow path arranged between the inlet and outlet means, theinlet and outlet means sealing the interior of the pump and thereby theflow path in an initial sterile condition, wherein a fluid connectionmeans is arranged within the interior of the pump in the initialcondition, the fluid connection means comprising an inlet end and anoutlet, whereby the fluid connection means is arranged to be movedbetween the initial condition and to an operating condition in which theinlet end projects from the pump inlet means, whereby a fluidcommunication can be established between the fluid supply and theinterior of the pump via the fluid connection means and with the outletof the fluid connection means being arranged in the flow path.

The transcutaneous device unit may be supplied with e.g. a needleprojecting from the mounting surface, however, to limit the risk ofaccidental needle injuries, the distal end of the transcutaneous deviceis advantageously movable between an initial position in which thedistal end is retracted relative to the mounting surface, and anextended position in which the distal end projects relative to themounting surface. Depending on the intended method of mounting thedevice on the user, the transcutaneous device may be moved between thetwo positions as the two units are connected to each, as would beappropriate in case the transcutaneous device unit is mounted on theskin of the user before the reservoir unit is connected. However, incase the two units are intended to be connected to each other beforeassembled units are mounted on the skin of the user, the transcutaneousdevice unit advantageously comprises user-actuatable actuation means formoving the pointed end of the transcutaneous device between the initialand the extended position.

To prevent inadvertent actuation of the transcutaneous device before thetwo units are assembled, the transcutaneous device unit may comprisemeans for blocking the actuation means, the blocking means beingreleased when the transcutaneous device unit and the reservoir unit aresecured to each other, thereby allowing the actuation means to beactuated.

To further reduce the likelihood of transcutaneous device injuries, thedistal end of the transcutaneous device may be movable between theextended position in which the distal end projects relative to themounting surface, and a retracted position in which the distal end isretracted relative to the mounting surface. Correspondingly, thecombined device may comprise user-actuatable retraction means for movingthe distal end of the transcutaneous device between the extended and theretracted position when the retraction means is actuated. To preventre-use of the transcutaneous device, the transcutaneous device may bepermanently locked in its retraced position.

To prevent user-errors the actuation means for introducing thetranscutaneous device may in an initial condition cover the retractionmeans, actuation of the actuation means uncovering the retraction means.For example, the actuation means may be in the form of gripping means(e.g. a strip) which is removed from the device, whereby removaltriggers transcutaneous device insertion and at the same time uncoversthe retraction for withdrawing the transcutaneous device.

As described above, the expelling assembly may be activated anddeactivated when the two units are assembled and disassembled, however,the actuation and retraction means may also be used to activaterespectively deactivate the expelling assembly. Just as for the initialconnection between the pump and the reservoir, the initial activation ofthe expelling assembly may result in electronic control means beingactivated resulting in start of pumping action, whereas subsequentdeactivation will only deactivate the actual pump action, the controlmeans still being active (e.g. counting the time since initialactivation of the control means).

In the above disclosure of the invention the two units have beendescribed primarily as “unitary” units, however, this is only anexemplary configuration and these two “main” units may in case it isdeemed desirable be subdivided into further units. For example, thereservoir unit may be provided with an exchangeable control unit, thisallowing different types of control units to be connected to thereservoir unit per se. e.g. a first type of control unit may provide asingle delivery profile, a second control unit may be programmable tothereby modify the delivery pattern, or a control third unit maycomprise means allowing the control unit to communicate with externalmeans. In the latter case the control unit may be controlled using acordless remote control. Correspondingly, the reservoir may beexchangeable allowing different sizes of reservoirs or different typesof drugs to be used.

In a further aspect of the invention, a transcutaneous device unit isprovided as described above and being adapted to be used in combinationwith a reservoir unit as disclosed above. Correspondingly, the inventionalso provides a reservoir unit as disclosed above, the reservoir unitbeing adapted to be used in combination with a transcutaneous deviceunit as disclosed above. In an exemplary embodiment such atranscutaneous device unit may be provided with a hollow needlecomprising a pointed distal end with an outlet opening and being adaptedto penetrate the skin of a subject, and a pointed proximal end with aninlet opening forming a fluid inlet means, the fluid inlet means beingadapted to be arranged in fluid communication with a fluid supply. Bythis arrangement the needle provides a hydraulically stiff fluidcommunication between the needle inlet and outlet openings (e.g. madefrom metal), this allowing early occlusion detection by monitoring apressure build-up upstream of the needle.

In a yet further aspect, a system is provided comprising a first needleunit and a first reservoir unit as disclosed above in combination with aleast one further needle unit or reservoir unit as disclosed above, thefurther unit(s) having different capabilities than the first units. Thedifferent capabilities may relate to any constructional feature of theunits, e.g. the type of needle, the type of user-actuatable means, thetype of delivery/pump means, or the type of reservoir/drug.

More specifically, in an exemplary embodiment a system is providedcomprising a transcutaneous device unit as disclosed above, and aplurality of reservoir units, each comprising a reservoir containing afluid drug, and an expelling assembly for expelling fluid drug from thereservoir. The transcutaneous device unit and the reservoir unitscomprise mating coupling means allowing a reservoir unit to be securedto the transcutaneous device unit to provide fluid communication betweenthe reservoir and the transcutaneous device, wherein each combination ofa transcutaneous device unit and a reservoir unit provides an assemblyhaving different capabilities. The different capabilities may berealized providing e.g. reservoir units with different amounts of thesame drugs, reservoir units with different drugs or variants of a givendrug, reservoir units adapted to expel drug at different preset rates,reservoir units adapted to expel at fixed respectively selectable rates.One of the reservoir units may be provided with a processor controllingthe expelling assembly and a receiver operatable coupled to thecontroller for receiving flow instructions from a separate controldevice and delivering the flow instructions to the processor. Thereceiver may be a wireless receiver. The reservoir units may further beprovided with different input means (e.g. for wireless or non-wirelessconnection, or manual input), or different output means (e.g. forwireless or non-wireless connection, different display means, ordifferent alarm means).

In a further exemplary embodiment, a system is provided comprising aplurality of transcutaneous device units as described above, and areservoir unit comprising a reservoir containing a fluid drug, and anexpelling assembly for expelling fluid drug from the reservoir. Thetranscutaneous device units and the reservoir unit comprise matingcoupling means allowing a transcutaneous device unit to be secured tothe reservoir unit to provide fluid communication between the reservoirand the transcutaneous device, wherein each combination of atranscutaneous device unit and a reservoir unit provides an assemblyhaving different capabilities. The different capabilities may berealized by providing the transcutaneous device units with differenttranscutaneous devices such as a hollow subcutaneous needle, a cannulaand insertion needle assembly, and a micro needle array, by providingdifferent adhesives, by providing different insertion or retractionmeans, or by providing different coupling means.

In a yet further exemplary embodiment, a system is provided comprising atranscutaneous device unit comprising a transcutaneous device and amounting surface adapted for application to the skin of a subject, areservoir unit comprising a reservoir containing a fluid drug, and atleast a portion of an expelling assembly for expelling fluid drug fromthe reservoir, and a plurality of control units, each comprising acontroller for controlling an expelling assembly, each having differentcapabilities. The transcutaneous device unit and the reservoir unitcomprise mating coupling means allowing the reservoir unit to be securedto the transcutaneous device unit to provide fluid communication betweenthe reservoir and the transcutaneous device, and the controller unitsand the reservoir unit comprise mating coupling means allowing acontroller unit to be secured to the reservoir unit to control theexpelling assembly, whereby each combination of a transcutaneous deviceunit, a reservoir unit and a control unit provides an assembly havingdifferent capabilities. The control units may have different controlfunctions as described above in respect of a system comprising aplurality of reservoir units. In an alternative configuration thereservoir unit and the transcutaneous device unit may be provided as aunitary structure adapted to cooperate with the control unit.

The present invention also provides a method comprising the steps ofproviding a transcutaneous device unit comprising a transcutaneousdevice and a mounting surface, providing a reservoir unit comprising areservoir adapted to contain a fluid drug, and an expelling assembly forexpelling fluid drug from the reservoir, the method comprising thefurther step of assembling the transcutaneous device unit and thereservoir unit to provide a fluid communication between the reservoirand the transcutaneous device. The fluid communication between thetranscutaneous device and the reservoir may be established when the twounits are assembled or it may be established when the assembled deviceis further actuated, both options being covered by the above definition.The method may comprise the further steps of mounting the mountingsurface to a skin surface of a subject, and, after mounting the mountingsurface to the skin surface of the subject, actuating the transcutaneousdevice to establish a fluid communication between the reservoir and thesubject.

A further method provides a drug delivery device dispensing a drug at apreset rate, the method comprising the steps of providing a systemcomprising a transcutaneous device unit comprising a transcutaneousdevice and a mounting surface adapted for application to the skin of asubject, the system further comprising a plurality of reservoir units,each comprising a reservoir containing a fluid drug, and an expellingassembly for expelling fluid drug from the reservoir at a preset rate,selecting a reservoir unit having a desired preset rate, and assemblingthe transcutaneous device unit and the selected reservoir unit toprovide a fluid communication between the reservoir and thetranscutaneous device.

In the above disclosure the present invention has been described withreference to a drug delivery device, however, the concept of theinvention can be regarded as a modular system providing a number ofadvantages. Thus, the transcutaneous device unit may also be in the formof a needle sensor and the “reservoir unit” may correspondingly be inthe form of a device adapted to transmit and/or process data acquiredvia the sensor.

As used herein, the term “drug” is meant to encompass anydrug-containing flowable medicine capable of being passed through adelivery means such as a hollow needle in a controlled manner, such as aliquid, solution, gel or fine suspension. Representative drugs includepharmaceuticals such as peptides, proteins, and hormones, biologicallyderived or active agents, hormonal and gene based agents, nutritionalformulas and other substances in both solid (dispensed) or liquid form.In the description of the exemplary embodiments reference will be madeto the use of insulin. Correspondingly, the term “subcutaneous” infusionis meant to encompass any method of transcutaneous delivery to asubject. Further, the term needle (when not otherwise specified) definesa piercing member adapted to penetrate the skin of a subject.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following the invention will be further described with referencesto the drawings, wherein

FIGS. 1-3 shows in perspective views sequences of use for a firstembodiment of a drug delivery device,

FIG. 4 shows in a non-assembled state a needle unit and a reservoir unitfor a further embodiment of a drug delivery device,

FIG. 5 shows an exploded view of the needle unit of FIG. 4,

FIG. 6 shows a perspective view of the needle unit of FIG. 4 in a firststate,

FIG. 7 shows a perspective view of the needle carrier of FIG. 5,

FIG. 8 shows a perspective view of the needle unit of FIG. 4 in a secondstate,

FIG. 9 shows a side view of the needle unit of FIG. 4,

FIG. 10 shows a further perspective view of the needle unit of FIG. 4,

FIG. 11 shows perspective view of the interior of the reservoir unit ofFIG. 4,

FIG. 12 shows an exploded view of a further reservoir unit,

FIGS. 13A and 13B show in a schematic representation a transcutaneousdevice in the form of a cannula and insertion needle combination,

FIG. 14 shows a side view of a medical device mounted on a curved skinsurface,

FIG. 15 shows medical device comprising a patch unit and an inserterunit,

FIG. 16 shows an exploded view of the device of FIG. 15,

FIG. 17 shows the device of FIG. 16 from below,

FIGS. 18A-18F show different states of use of the device of FIG. 15,

FIG. 19 shows an exploded view of a patch unit comprising an inserterassembly,

FIG. 20A shows in an exploded view details of the inserter assembly ofFIG. 19,

FIG. 20B shows the details of FIG. 20A in an assembled state,

FIGS. 21A-21D show different states of use of the device of FIG. 19,

FIG. 22 shows in an exploded view a schematic representation of atranscutaneous device unit,

FIGS. 23A-23D show in different actuation states a mechanism forinsertion of a cannula,

FIG. 24 shows an exploded view of an inserter,

FIGS. 25A-25C show the relationship between the needle holder, thecannula holder, and the spring corresponding to the states shown inFIGS. 23A-23C,

FIGS. 26A and 26B show in a non-assembled respectively assembled state acannula unit and a reservoir unit for a further embodiment of a drugdelivery device,

FIG. 27 shows an alternative configuration for the device of FIG. 21A,

FIG. 28 shows a medical device with a modular reservoir unit,

FIG. 29 shows a modular system for a medical device,

FIGS. 30A-30C show infusion systems comprising delivery device, analytesensor and remote control unit, and

FIGS. 31A and 31B show a modular medical sensor device in differentstages.

In the figures like structures are mainly identified by like referencenumerals.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

When in the following terms such as “upper” and “lower”, “right” and“left”, “horizontal” and “vertical” or similar relative expressions areused, these only refer to the appended figures and not to an actualsituation of use. The shown figures are schematic representations forwhich reason the configuration of the different structures as well asthere relative dimensions are intended to serve illustrative purposesonly.

Firstly, with reference to FIGS. 1-3 an embodiment of a medical devicefor drug delivery will be described focusing primarily on the directlyuser-oriented features. The transcutaneous device unit 2 comprises atranscutaneous device in the form of a hollow infusion device, e.g. aneedle or soft cannula, and will thus in the following be termed aneedle unit, however, the needle may be replaced with any desirabletranscutaneous device suitable for delivery of a fluid drug or forsensing a body parameter.

More specifically, FIG. 1 shows a perspective view of medical device inthe form of a modular skin-mountable drug delivery device 1 comprising apatch-like needle unit 2 (which may also be denoted a patch unit) and areservoir unit 5. When supplied to the user each of the units arepreferably enclosed in its own sealed package (not shown). Theembodiment shown in FIG. 1 comprises a patch unit provided with aninsertable steel needle, however, the embodiment is exemplary of how touse a patch unit with an insertable transcutaneous device, e.g. needle,cannula or sensor. In case an actual embodiment requires the patch unitto be mounted on the skin and the transcutaneous device inserted beforea reservoir or other unit can be attached, it follows that the method ofuse would be adopted correspondingly.

The needle unit comprises a flexible patch portion 10 with a loweradhesive mounting surface adapted for application to the skin of a user,and a housing portion 20 in which a hollow infusion needle (not shown)is arranged. The needle comprises a pointed distal end adapted topenetrate the skin of a user, and is adapted to be arranged in fluidcommunication with the reservoir unit. In the shown embodiment thepointed end of the needle is movable between an initial position inwhich the pointed end is retracted relative to the mounting surface, andan extended position in which the pointed end projects relative to themounting surface. Further, the needle is movable between the extendedposition in which the pointed end projects relative to the mountingsurface, and a retracted position in which the pointed end is retractedrelative to the mounting surface. The needle unit further comprisesuser-gripable actuation means in the form of a first strip-member 21 formoving the pointed end of the needle between the initial and the secondposition when the actuation means is actuated, and user-gripableretraction in the form of a second strip-member 22 means for moving thepointed end of the needle between the extended and the retractedposition when the retraction means is actuated. As can be seen, thesecond strip is initially covered by the first strip. The housingfurther comprises user-actuatable male coupling means 31 in the form ofa pair of resiliently arranged hook members adapted to cooperate withcorresponding female coupling means on the reservoir unit, this allowingthe reservoir unit to be releasable secured to the needle unit in thesituation of use. A flexible ridge formed support member 13 extends fromthe housing and is attached to the upper surface of the patch. In use aperipheral portion 12 of the patch extends from the assembled device asthe reservoir unit covers only a portion 11 of the upper surface of thepatch. The adhesive surface is supplied to the user with a peelableprotective sheet.

The reservoir unit 5 comprises a pre-filled reservoir containing aliquid drug formulation (e.g. insulin) and an expelling assembly forexpelling the drug from the reservoir through the needle in a situationof use. The reservoir unit has a generally flat lower surface adapted tobe mounted onto the upper surface of the patch portion, and comprises aprotruding portion 50 adapted to be received in a corresponding cavityof the housing portion 20 as well as female coupling means 51 adapted toengage the corresponding hook members 31 on the needle unit. Theprotruding portion provides the interface between the two units andcomprises a pump outlet and contact means (not shown) allowing the pumpto be started as the two units are assembled. The lower surface alsocomprises a window (not to be seen) allowing the user to visuallycontrol the contents of the reservoir before the two units areconnected.

First step in the mounting procedure is to assemble the two units bysimply sliding the reservoir unit into engagement with the needle unit(FIG. 2). When the hook members properly engage the reservoir unit a“click” sound is heard (FIG. 3) signaling to the user that the two unitshave been properly assembled. If desired, a visual or audible signal mayalso be generated. Thereafter the user removes the peelable sheet 14 touncover the adhesive surface where after the device can be attached to askin surface of the user, typically the abdomen. Infusion of drug isstarted by gripping and pulling away the actuation strip 21 as indicatedby the arrow whereby the needle is inserted followed by automatic startof the infusion. The needle insertion mechanism may be supplied in apre-stressed state and subsequently released by the actuation means orthe needle insertion may be “energized” by the user. A “beep” signalconfirms that the device is operating and drug is infused. The reservoirunit is preferably provided with signal means and detection meansproviding the user with an audible alarm signal in case of e.g.occlusion, pump failure or end of content.

After the device has been left in place for the recommended period oftime for use of the needle unit (e.g. 48 hours)—or in case the reservoirruns empty or for other reasons—it is removed from the skin by grippingand pulling the retraction strip 22 which leads to retraction of theneedle followed by automatic stop of drug infusion where after the stripwhich is attached to the adhesive patch is used to remove the devicefrom the skin surface.

When the device has been removed the two units are disengaged bysimultaneously depressing the two hook members 31 allowing the reservoirunit 5 to be pulled out of engagement with the needle unit 2 which canthen be discarded. Thereafter the reservoir unit can be used again withfresh needle units until it has been emptied.

FIG. 4 shows a further embodiment of medical device 500 substantiallycorresponding to the embodiment of FIG. 1, the device comprising atranscutaneous device unit 502 and a process unit 505, Morespecifically, the transcutaneous device unit comprises a flexible patchportion (in the shown embodiment formed by a perforated sheet member570) comprising an upper surface and a lower surface, the lower surfacebeing adapted for application to the skin of a subject, a first housing503 comprising a first coupling with two male coupling elements 511, anda transcutaneous device arranged in the housing (see below). Twosupporting ridge members 561 extend from the first housing and areattached to the upper surface of the sheet member. The supports serve asattachment supports for the first housing, however, they may also serveto control the distance between the lower surface or the process unitand the patch. When the second unit is configured to accommodate atleast partially the support members, e.g. in corresponding cut-outportions or grooves 504 (see FIG. 12), the supports may also serve tolaterally stabilize the connection between the two units. The processunit comprises a second housing 501 with a lower surface and a secondcoupling arranged at a peripheral portion of the second housing, and aprocess assembly, e.g. a pump assembly as will be described below. Inthe shown embodiment the process unit has a generally flat rectangularshape with a cut-off end portion defining the interface with thetranscutaneous device unit and also comprising the coupling in the formof two female coupling elements 506 arranged at each side of the endportion. Corresponding to FIGS. 1-3, the first and second couplings canbe connected to each other with the upper surface of the patch facingtowards the lower surface of the second housing. Due to the peripheralarrangement of the second coupling the flexible patch portion facingtowards the lower surface of the second housing is free to move relativethereto, the degree of freedom being determined by the flexibility ofthe patch and supports if so provided and, of course, the surface towhich the transcutaneous device unit is mounted.

In the shown embodiment the patch portion has the same general shape asthe combined device albeit somewhat larger. In alternative embodimentsthe patch may comprise openings or cut-out portions. For example, anarea between the two support legs may be cut out allowing the underlyingskin to better breath.

FIG. 14 shows a side view of the assembled device 500 mounted on acurving skin surface 590. As appears, the flexible patch portion withits support members is allowed to follow the curvature of the skin, thiscreating a ventilation space between the process unit and the patchportion.

FIG. 5 shows an exploded perspective view of the needle unit comprisingan upper housing portion 510, a needle carrier 520 and a thereto mountedinfusion needle 530, an actuation member 540, a release member 550, alower housing portion 560 and a sheet member 570 with a lower adhesivemounting surface 571. The actuation member comprises a user gripableportion 541 and a needle actuation portion 542, and the release membercomprises a user gripable portion 551 and a needle retraction portion552. In the assembled state as shown in FIG. 6, the upper and lowerhousing portions form a housing 503 in which the needle and the needlecarrier is mounted, the actuation and release members being operatableconnected to the needle carrier with the user gripable portions arrangedoutside the housing. The sheet member further comprises an opening 572arranged in register with a lower protrusion 565 provided around theexit aperture for the transcutaneous device, just as the sheet isprovided with a large number of small perforations to improvebreathability through the sheet. The housing 503 is provided with useractuatable coupling means 511 allowing a reservoir unit to be attachedto and released from the needle unit 505, the reservoir unit comprisingcorresponding mating coupling means 506 as well as a display 587. Thedisplay may indicate e.g. proper function of the unit, the amount ofdrug in the reservoir or different error conditions.

As seen is the user gripable portion 551 of the release member initiallycovered by a portion of the actuation member, this reducing theprobability that the user erroneously uses the release member instead ofthe actuation member. Further, the actuation and release members (orportion thereof) may be colour coded to further assist the user tocorrectly use the device. For example, the actuation member may be greento indicate “start” whereas the release member may be red to indicate“stop”.

FIG. 7 shows in perspective the needle carrier 520 with the needle 530and the needle actuation portion 542 of the actuation member 540. Theneedle actuation portion comprises two legs 543 allowing it to sliderelative to the housing, the legs being arranged through respectiveopenings 563 in the housing. The needle carrier is adapted to beconnected to a hinge member 562 of the lower housing portion to therebyallow the needle carrier and thereby the needle to pivot correspondingto a pivoting axis defined by a hinge. In the shown embodiment is theneedle carrier in the form a bent sheet metal member, the carriercomprising an upper arm 521 and a lower arm 522 connected to each otherby a hinge portion 523 allowing the lower arm to pivot relative to theupper arm and corresponding to the pivoting axis. The lower arm forms atray in which the hollow infusion needle 530 is mounted (e.g. by weldingor adhesive), the needle having a distal pointed portion 531 adapted topenetrate the skin of the subject, the distal portion extendinggenerally perpendicular to the mounting surface of the needle unit, anda proximal portion 532 arranged substantially corresponding to thepivoting axis and adapted to engage a fluid supply. Thus, when a portionof the upper arm is mounted in the housing, the lower arm can pivotbetween a first retracted position in which the distal portion of theneedle is retracted within the housing, and a second extended positionin which the distal portion projects relative to the mounting surface.In the shown embodiment the needle carrier provides the drive means formoving the lower arm between the two positions. This may as in thepresent embodiment be provided by the elastic properties of the sheetmaterial per se corresponding to the hinge portion, or alternatively anadditional spring may be provided between the two arms to thereby urgethem apart. To lock the lower part in an energized, releasable firstposition, the upper arm is provided with a flexible release arm 526comprising a catch 527 supporting and arresting the lower arm in itsfirst downwardly biased position, as well as a release portion 528engaging a ramp surface 544 of the needle actuation portion 542, thecatch further comprising an inclined edge portion 529 adapted to engagethe lower arm when the latter is moved from its extended to itsretracted position as will be described in greater detail below.

To actuate the needle the user grips the flexible strip forming the usergripable portion 541 (which preferably comprises adhesive portions tohold it in its shown folded initial position) and pulls the needleactuation portion 542 out of the housing, the actuation member 540thereby fully disengaging the housing. More specifically, when the rampsurface 544 is moved it forces the latch 527 away from the lower arm tothereby release it, after which the release portion 528 disengages theramp allowing the two legs to be pulled out of the housing. As seen inFIG. 8, when the actuation member is removed the user gripable portion551 of the release member is exposed. As for the actuation member, theuser gripable portion of the release member preferably comprisesadhesive portions to hold it in its shown folded initial position.

In the shown embodiment the release member is in the form of a stripformed from a flexible material and having an inner and an outer end,the strip being threaded through an opening 512 in the housing, thestrip thereby forming the user gripable portion 551 and the needleretraction portion 552, the inner end of the strip being attached to thehousing and the outer end of the strip being attached to a peripheralportion of the sheet member 570 or, alternatively, a peripheral portionof the housing. In the projection shown in FIG. 9 the release member isshown in its initial position, the retraction portion forming a loop 555arranged below the lower arm of the needle carrier, this positionallowing the lower arm to be moved to its actuated position and therebythe needle to its extended position.

When the user decides to remove the needle unit from the skin, the usergrips the user gripable portion 551, lifts it away from the housing andpulls it upwardly whereby the loop shortens thereby forcing the lowerarm upwardly, this position corresponding to an intermediate releasestate. By this action the lower arm engages the inclined edge portion529 of the catch 527 thereby forcing it outwardly until it snaps backunder the lower arm corresponding to the position shown in FIG. 7. Asthe actuation member 540 has been removed from the needle unit, theneedle carrier is irreversibly locked in its retracted position. Whenthe user further pulls in the release member, the peripheral portion ofthe sheet member to which the release member is attached will be liftedoff the skin, whereby the needle unit with its attached reservoir unitcan be removed from the skin, this as described above.

Advantageously, the actuation and release members may be formed andarranged to communicate with the reservoir unit (not shown). Forexample, one of the legs of the actuation member may in its initialposition protrude through the housing to thereby engage a correspondingcontact on the reservoir unit, this indicating to the reservoir unitthat the needle unit has been attached, whereas removal of the actuationmember will indicate that the needle has been inserted and thus thatdrug infusion can be started. Correspondingly, actuation of the releasemember can be used to stop the pump.

In FIG. 10 the side of the needle unit 502 which connects to thereservoir unit is shown. In addition to the two ridge members 561 andthe user actuatable coupling means 511 the needle unit comprises furtherstructures which connects to and/or engages the reservoir unit toprovide a functional interface with the reservoir unit. Morespecifically, the needle unit comprises a fluid inlet provided by thepointed proximal portion 532 of the needle projecting from the needleunit and adapted to engage a fluid outlet of the reservoir unit, anactuator 515 projecting from the needle unit and adapted to engage andactuate a fluid connector in the reservoir unit (see below), and firstand second contact actuators 548, 558 adapted to engage correspondingcontacts on the reservoir unit. The first contact actuator is providedby the distal end of one of the legs 543 of the needle actuatorprojecting through an opening in the housing, and the second contactactuator is provided by a hinged portion of the housing connected to theneedle retraction portion 552 of the release member 550. When the needleunit is first connected to the reservoir unit both contact actuatorswill protrude from the housing and engage the corresponding contacts onthe reservoir unit thereby indicating that that a needle unit has beenconnected. When the needle is actuated the first contact actuator willbe withdrawn and thereby disengage the corresponding contact on thereservoir unit to start pump actuation. When the needle is retracted thesecond contact actuator will pivot and disengage the correspondingcontact on the reservoir unit to stop pump actuation.

FIG. 11 shows the reservoir unit with an upper portion of the housingremoved. The reservoir unit comprises a reservoir 595 and an expellingassembly comprising a pump assembly 300 and control and actuation means580, 581 therefore. The pump assembly comprises an outlet 322 forconnection to a transcutaneous access device (e.g. the needle 530) andan opening 323 allowing an internal fluid connector to be actuated, seebelow. The reservoir 560 is in the form of prefilled, flexible andcollapsible pouch comprising a needle-penetratable septum adapted to bearranged in fluid communication with the pump assembly, see below. Theshown pump assembly is a mechanically actuated membrane pump, however,the reservoir and expelling means may be of any suitable configuration.

The control and actuation means comprises a pump actuating member in theform of a coil actuator 581 arranged to actuate a piston of the membranepump, a PCB or flex-print to which are connected a microprocessor 583for controlling, among other, the pump actuation, contacts 588, 589cooperating with the contact actuators on the needle unit, signalgenerating means 585 for generating an audible and/or tactile signal, adisplay (not shown) and an energy source 586. The contacts arepreferably protected by membranes which may be formed by flexibleportions of the housing.

The membrane pump may comprise a piston-actuated pump membrane withflow-controlled inlet- and outlet-valves. The pump has a general layeredconstruction comprising a number of body members between which areinterposed flexible membrane layers, whereby a pump chamber, inlet andoutlet valves, and one or more safety valves can be formed. The pumpfurther comprises a fluid connector in the form of hollow connectionneedle slideably positioned within the pump behind the connectionopening 323, this allowing the pump to be connected with reservoir. Fora more detailed description of such a membrane pump reference is made toapplicants co-pending application PCT/EP2006/060277, which is herebyincorporated by reference.

In FIG. 12 an exploded view of the reservoir unit 505 of FIG. 4 isshown, the unit comprising an upper housing member 507, a lower housingmember 508 with a transparent area 509 and grooves 504 to receive theridge members 561 extending from the needle unit, a flexible reservoir595 with a rounded edge portion 597 on which a septum member 596 ismounted, a pump assembly 300 with actuator and a circuit board (notshown) arranged above the reservoir and comprising electronic componentsfor controlling actuation of the pump. The upper and lower housingmembers comprise reservoir mounting means in the form of opposed upperand lower ridge portions 591 (the lower not seen) adapted to engage andmount the reservoir in the housing. Each ridge portion comprises acentral cut-out portion 592 adapted to engage the septum member on itsopposed surfaces when the housing members are assemble thereby lockingthe reservoir in place within the housing. The degree of locking will bedetermined by the pressure exerted on the septum member, the elasticproperties of the septum member and the friction between the ridge andthe septum member. On each side of the cut-out portion the ridgeportions comprise a straight portion 593 which may aid in mounting thereservoir in the housing. The straight portions may engage the initiallyprefilled reservoir to help lock it in place, however, as the reservoiris emptied and flattens this grip may lessen. In contrast, theengagement with the septum is adapted to properly hold the reservoir inplace as the reservoir is emptied. The straight portions may also beadapted to pinch and fully flatten the reservoir thus serving as anadditional mounting means. Additional mounting means (not shown) mayengage and grip the reservoir at other locations, e.g. along the weldededges 598.

In the above described embodiments, the transcutaneous device has beenin the form of a unitary needle device (e.g. an infusion needle as shownor a needle sensor (not shown), however, the transcutaneous device mayalso be in the form of a cannula or a sensor in combination with aninsertion needle which is withdrawn after insertion thereof. Forexample, the first needle portion may be in the form of a (relativelysoft) infusion cannula (e.g. a Teflon® cannula) and a there througharranged removable insertion needle. This type of cannula needlearrangement is well known from so-called infusion sets, such infusionsets typically being used to provide an infusion site in combinationwith (durable) infusion pumps.

Thus, FIGS. 13A and 13B show in a schematic representation how a cannulaand insertion needle combination can be arranged within a housing 601 ofin a given medical device 600 (partly shown), e.g. an infusion device oran infusion set. More specifically, the medical device comprises atranscutaneous assembly 650 comprising a combination of a relativelysoft cannula 651 (which e.g. may be of the soft “Teflon®” type) carriedby a lower member 653 and a pointed insertion needle 661 (e.g. made frommedical grade stainless steel) slideably arranged within the cannula andcarried by an upper member 663, both members being mounted to allowaxial displacement of the cannula respectively the insertion needle. Thecannula comprises a proximal inlet (not shown) allowing it to be or tobe arranged in fluid communication with a fluid source. The medicaldevice further comprises a base plate 620 with an opening 621 for thecannula as well as a release member 622. The lower member comprises anelastomeric seal 652 through which the insertion needle is arranged. Thecannula and the insertion needle may be straight or curved dependentupon how the two members are mounted in the device, e.g. arcuatecorresponding to a pivoting axis or straight corresponding to linearmovement as illustrated. The upper member comprises a coupling member667 locking the members together in an initial position with distal endof the insertion needle extending from the distal opening of the cannulaas shown in FIG. 13A, and the base plate comprises coupling member 657for locking the lower member in an extended position with distal end ofthe cannula extending through the opening in the base plate (see FIG.13B). Between the housing of the device and the upper member a firstspring 668 is arranged biasing the upper member upwards.Correspondingly, the device also comprises a second spring 658 biasingthe lower member upwardly. The medical device further comprises agripping tab 676 and a pulling member 677 corresponding to theembodiment shown in FIG. 1.

In a situation of use the assembly is moved downwardly, either manuallyor by a releasable insertion aid, e.g. a spring loaded member actingthrough an opening in the housing (not shown) whereby the cannula withthe projecting insertion needle is inserted through the skin of asubject. In this position the lower member engages the coupling member657 to thereby lock the cannula in its extended position, just as thecoupling member 667 is released by the release member 622 therebyallowing the upper member to return to its initial position by means ofthe first spring.

When the user intends to remove the delivery device from the skinsurface, the user grips the gripping portion of the tab and pulls it ina first direction substantially in parallel with the skin surface, bywhich action the flexible strip 677 releases the coupling member 657from the lower member whereby the lower member and thereby the cannulais retracted by means of the second spring. When the cannula has beenwithdrawn from the skin, the user uses the now unfolded tab to pull offthe entire delivery device from the skin surface, for example by pullingthe tab in a direction away from the skin surface.

With reference to FIGS. 15-18 a medical device 700 will be describedcomprising a cannula and an insertion needle (in the following also“needle” for short). The cannula may be in the form of what istraditionally referred to as a “soft catheter” or a “Teflon catheter”.The device comprises two portions, a patch unit 710 comprising a housingmounted on a patch of flexible sheet material, and an inserter unit 720removably coupled to the patch housing. The inserter housing initiallycomprises the entire insertion mechanism including the cannula. Whenactuated the cannula becomes attached to the patch housing where afterthe inserter housing with the remaining inserter mechanism can bedetached and discarded.

More specifically, the patch unit comprises a flexible sheet 721 with alower adhesive surface and an opening 722 for the cannula, a patchhousing with top 723 and base 724 portions, the base portion beingattached to the upper surface of the sheet. The patch housing comprisesan opening 725 for the cannula arranged just above the opening in thesheet, as well as a coupling in the form of two flexible arms 726allowing the inserter to be attached.

The inserter unit comprises an inserter housing with top 733 and base734 portions, the base portion comprising two walls 735 with upperinclined edges serving as a ramp 736 for an inserter assembly 740. Theinserter assembly comprises an inserter 750, a needle holder 760comprising a needle 761 protruding there from, a cannula holder 770 witha cannula 771 protruding there from, the cannula comprising a proximalneedle penetratable septum, two springs 751 mounted on respective springguides 752 on the inserter, and a release and retraction strip 780 (seeFIG. 18A). The strip comprises a proximal end projecting from thehousing and a distal end attached to the needle holder, the stripforming a loop portion attached to the inserter. The inserter and thecannula holder are each provided with pairs of grooves 755, 775 allowingthe inserter and the cannula to slide on the ramp. The insertercomprises an opening 753, an inclined ramp member 754 and a lockingprojection 757 adapted to engage a corresponding opening 737 in thehousing. The needle holder comprises a flexible release arm 763 with anupwardly protruding catch 762, and the cannula holder comprises a pairof coupling elements 772 for engagement with the patch housing. In aninitial assembled state (see FIG. 17) the cannula holder is arranged infront of the inserter and the needle holder is arranged below theinserter with the needle positioned through the septum and within thecannula and projecting there from, and with the catch 762 protrudingthrough the opening 753. As an example, the cannula may be a softcatheter with an OD of 0.7 mm and an ID of 0.4 mm and the needle mayhave an OD of 0.4 mm (G27). The inner surface of the inserter housingcomprises a ramp 738 and a hold 739 adapted to engage the inserterassembly as described below. In a fully assembled initial state theinserter assembly is locked in place by the locking projections 757engaging the opening 737 in the inserter housing, the springs beingarranged in a compressed state between the inserter and the inserterhousing. Upper guides 731 in the inserter housing secures that theinserter assembly can move only along the inclined ramp.

Next, with reference to FIGS. 18A-18F operation of a medical device ofthe above-outlined construction for insertion of a soft catheter will bedescribed. The user first removes a protective sheet covering theadhesive surface of the patch and arranges the patch on a suitable skinportion of a subject, e.g. the abdomen. In the start position (see FIG.18A) the soft catheter holder with a soft catheter is placed in front ofthe inserter. The needle holder is connected to the inserter, which isloaded with springs (see FIG. 15), all integrated in the inserterhousing. The inserter needle is arranged inside the soft catheter withits pointed needle tip e.g. 2 mm in front of the soft catheter. Next theuser pulls the strip which releases the inserter from the housing, thisallowing the inserter assembly with soft catheter and needle holder tostart move forwards pushed by the springs. As appears, by this actionthe strip is released from the needle holder. By the initial travel ofthe inserter assembly the inserter needle with soft catheter penetratesdermis 2-4 mm. During this movement the catch of the release arm on theneedle-holder engages the ramp placed on the inserter-housing (see FIG.18B). The ramp depresses the release arm in relation to its engagementwith the inserter, and finally arrests the release arm as it engages thehold at the end of the ramp, this temporary halting movement of theneedle holder. After needle movement has come to a halt, the inserterand the soft catheter holder continue forward movement driven by thesprings, thereby moving the soft catheter ahead of the needle an intosub-cutis. The needle holder is stopped until the soft catheter tip ise.g. 1-5 mm in front of needle tip. During this movement the release armon the needle holder is stopped by the hold in the housing, however, atthe same time the flexible arm is engaged by the ramp member on theinserter. This ramp depresses the release arm until it is lifted free ofthe hold where after it again engages the inserter (see FIG. 18C). Afterthe needle holder has re-engaged the inserter, the needle now followsthe soft catheters movement through sub-cutis to a final position, andthe needle can therefore act as guide for the soft catheter, with thetip of the needle e.g. 1-5 mm behind the tip of the soft catheter. Whenthe cannula reaches its final fully extended position the soft catheterholder is positioned in the patch-housing where it is locked in place(see FIG. 18D). As appears, the above-described actions all take placeautomatically driven by the springs and in a very short time, thisproviding minimum discomfort to the subject.

At this point the soft catheter has been placed at the desired place andwhat remains is for the user to withdraw the needle and remove theremaining inserter assembly and housing. In the shown embodiment theinserter is locked in place in its foremost position. The needle holderis released from the inserter and the needle is retracted by the userpulling the strip attached to the needle holder until the needle hasbeen locked in its fully retracted position with the distal pointed endarranged within the inserter housing (see FIG. 18E). In the shownembodiment the inserter serves to surround and protect the pointed endof the needle. Finally the user detaches the inserter housing from thepatch unit which can then be disposed off (see FIG. 18F). The cannula isnow ready to be connected to a fluid source, e.g. a reservoir unit asshown in FIG. 1 and of the same principal configuration as describedwith reference to FIGS. 11 and 12. Indeed, the interface of the pumpassembly 300 will have to be modified in order to connect to theproximal septum of the soft catheter or cannula instead of a pointedneedle end, i.e. the pump assembly will be provided with a pointedhollow needle establishing a fluid communication between the pumpassembly and the inserted cannula.

With reference to FIGS. 15-18 an embodiment comprising a separatecannula inserter has been described, however, a corresponding mechanismmay also be incorporated in a unitary patch unit. Such a design wouldindeed result in a larger patch housing, however, the user would nothave to detach and discard the inserter. For such a design the needlemay be hollow and comprise a proximal end, with the distal end of theneedle being in sealed fluid communication with the interior of thecannula when the needle has been arranged in its retracted position. Bythis arrangement a fluid communication can be provided between theproximal end of the needle and the cannula, this allowing the fluidcommunication to be established between the patch unit and the reservoirunit corresponding to the connection between the units in the FIGS. 5-12embodiment. In this case a delivery device would supply drug to thecannula via the hollow needle.

With reference to FIGS. 19-21 a further integrated concept will bedisclosed. The concept consists of an introducer needle surrounding acannula, e.g. a soft catheter. The 1-2 mm cutis or derma is penetratedby the needle and only the soft catheter is inserted into sub-cutis.Once the soft catheter is fully inserted, the needle is retracted. Sincethe needle is placed on the outside of the soft catheter, the softcatheter can be made in a smaller diameter compared to a concept inwhich the needle is arranged inside the needle and trauma in subcutis isthereby minimized, however, the larger diameter needle may cause largertrauma in the derma just as the cannula may be more susceptible tokinking and there may be less control when positioning the soft catheterin the subcutis. Also clotting during use may be more likely. Theseissues have to be considered when deciding on a specific concept and thespecific design parameters for such a concept.

Turning to an exemplary embodiment, the medical device is in the form ofa unitary patch unit 800 comprising a housing mounted on a patch offlexible sheet material, the inserter housing comprising the entireinsertion mechanism including the cannula.

More specifically, the patch unit comprises a flexible sheet 821 with alower adhesive surface and an opening 822 for the cannula (in thisembodiment a flexible soft catheter), a patch housing with top 823 andbase 824 portions (823′ indicates a top portion shown upside down), withthe base portion being attached to the upper surface of the sheet,wherein the top portion comprises a 45 degrees guide 825 for the cannulaholder (see below). The patch housing comprises an opening for thecannula and needle arranged just above the opening in the sheet, as wellas a coupling in the form of two flexible arms 826 allowing a deliverydevice to be attached. The base portion comprises two walls 835 withupper inclined edges serving as a ramp 836 for an inserter assembly 840.The inserter assembly comprises an inserter 850 with an attached needle861 and a cannula holder 870 attached to a cannula 871 and adapted formoving the cannula relative to the inserter and thereby the needle (seeFIGS. 20A and 20B). The inserter is provided with pairs of groovesallowing the inserter to slide on the ramp. The insertion mechanismfurther comprises a user-releasable spring (not shown) for moving theinserter and a strip (not shown) for moving the cannula holder relativeto the inserter. As an example, the soft catheter may have an OD of 0.4mm and an ID of 0.1 mm and the needle may have an OD of 0.7 mm and an ID0.4 mm (G22).

To save space in the patch housing, the soft catheter introducingmechanism is placed perpendicular in respect of the direction ofintroduction. The soft catheter 871 is placed in a groove 855 in theinserter that guides the soft catheter, the groove having a 90 degreesbend to change the direction of the soft catheter during theintroduction. As appears from FIGS. 20A and 20B when the catheter holder870 is moved across the inserter the soft catheter is extended in aperpendicular direction.

Next, with reference to FIGS. 21A-21D operation of a medical device ofthe above-outlined construction for insertion of a soft catheter will bedescribed. The user first removes a protective sheet covering theadhesive surface of the patch and arranges the patch on a suitable skinportion of a subject, e.g. the abdomen. In the start position (see FIG.21A) the inserter is arranged in its retracted position and the cannulaholder is arranged in its initial position. When the inserter isreleased (e.g. by pulling a strip to release a spring) the introducerneedle with the soft catheter inside penetrates dermis e.g. 2-4 mm (seeFIG. 21B). By continuous pulling the strip the user starts theintroducing of the soft catheter into sub-cutis by pulling the softcatheter holder across the inserter until the soft catheter is fullyintroduced (see FIG. 21C). After the soft catheter is fully introducedthe user continues the pulling of the strip and pulls the soft catheterholder further across the inserter, however, as the soft catheter holderhas reached the 45 degrees ramp, the inserter is forced backwards withthe same speed as the soft catheter is moved forward, the result is thatthe soft catheter stays in its final position and the introducer needleon the inserter is removed and disappears into the patch housing (seeFIG. 21D).

As the proximal end of the soft catheter is stationary, it may beprovided with a pointed hollow needle which would allow a reservoir unitbasically as shown in FIGS. 11 and 12 to be connected thereto.

FIG. 22 shows in an upper exploded view a drawing of a schematicrepresentation of a transcutaneous device unit (here a cannula unit)comprising a mechanism for inserting a soft cannula. The mechanism issimilar to the mechanism described with reference to FIGS. 19-21. Morespecifically, the unit comprises a bottom part 910 onto which is mounteda chassis part 920 thereby creating an interior in which the differentparts of the mechanism are arranged. In addition to the functionalportions of the bottom and chassis part the mechanism comprises a needleholder 930 with a needle mount 931 to which a needle 932 is mounted, acannula holder 940 comprising first and second gripping portions 941,942 adapted to engage the needle holder, and a hollow cannula assemblycomprising a soft, flexible cannula with a distal portion 951, anintermediate portion 952, and a proximal portion 953, the cannulaassembly further comprising a tubular housing member 955 adapted toengage an opening 922 in the chassis portion, an elastomeric tubularmember 956 in which the proximal end of the cannula is mounted, and aneedle pierceable elastomeric septum, the tubular member and the septumbeing arranged in the housing member thereby providing a fluid inletport for the hollow cannula. The mechanism further comprises acoil-formed torsion spring 960 comprising an actuator arm 961 with acurved distal end 962, the spring being arranged in a spring holder 970comprising a catch 971 allowing the spring to be mounted in apre-tensioned state. A release member 975 is provided comprising anouter end portion 976 adapted to engage e.g. a pump unit when the latteris mounted, and an inner end portion 977 adapted to engage and releasethe actuator arm from the spring holder. The bottom part comprises aninclined surface 911 with a guide 912 comprising a first guide groove913 arranged corresponding to a longitudinal axis of the unit, and asecond guide groove 914 arranged at an angle of 45 degrees relative tothe first guide groove.

In the assembled state the cannula holder is mounted on the needleholder with the gripping portions 941, 942 arranged on each side of theneedle mount 931, this allowing the cannula holder to slide along thelength of the needle holder, the two holders thereby forming aninserter. In an initial state the distal portion of the cannula ispositioned in the needle and the intermediate portion is positioned in achannel formed between the needle holder and the cannula holder, thecannula being mounted to the cannula holder by means of a flexiblemember on the first gripping portion.

In the assembled state the needle holder with the cannula holder mountedis arranged on the inclined surface and is allowed to slide up and down,with the guide grooves adapted to engage a guide member arranged on thelower surface of the cannula holder (not shown, see e.g. FIG. 24). Tocontrol movement of the needle holder the needle mount comprises a guideportion 933 with two opposed grooves adapted to engage a correspondingguide member 921 arranged on an interior surface of the chassis part. Asappears, in the shown schematic drawing the inclined surface 911 isshown without cut-out portions allowing the release member 975 and thespring holder 970 to be mounted (see below).

The bottom part 910 further comprises two opposed leg portions 918 eachwith a lobe 919, the lobes providing attachment points when the bottompart is mounted to a flexible sheet or foil member 901 comprising anadhesive lower mounting surface 904 allowing the transcutaneous unit tobe mounted on a skin surface of a subject. The sheet member comprises acentral opening 903 through which the needle and cannula is introduced,as well as a release liner 902. A cover portion 905 serves to close theinterior thereby forming a substantially closed housing.

With reference to FIGS. 23A-23D the mechanism described with referenceto FIG. 22 is shown in a partly assembled state, the chassis part andthe proximal portion of the cannula not being shown. The assembledembodiment differs slightly from the above-described embodiment,however, as the differences are small the same reference numerals areused.

The assembled embodiment primarily differs from the FIG. 23 embodimentin that the inclined surface 911 has been replaced with a number of wallmembers, the upper surfaces of these wall members in combinationproviding an inclined “surface” on which the needle holder is arranged,this allowing the spring 960 and release member 975 to be shownfunctionally correctly arranged.

FIG. 23A shows the assembly in an initial state with the needle holder930 in a first (or initial) retracted position with the needlecorrespondingly in its retracted position with the distal pointed endarranged within the housing. The cannula holder is positioned in aright-most position on the needle holder corresponding to its retractedposition. The distal portion of the cannula is positioned in the needlewith the distal end just within the distal end of the needle, and theintermediate portion is positioned in the channel formed between theneedle holder and the cannula holder (see FIG. 24), the cannula beinggripped by a flexible arm formed as part of the first gripping member941.

When a pump unit (not shown) is attached to the cannula unit the pumpunit engages and pushes the outer end portion 976 of the release member975, thereby releasing the spring actuator arm 961. The actuator thenstarts to turn clockwise (as seen in the figure) and engages a rearsurface of the needle member pushing it forward to its extended positionas seen in FIG. 23B. During this movement the needle holder is guidedlinearly by engagement with the guide member 921 arranged on an interiorsurface of the chassis part, whereas the cannula correspondingly isguided linearly to its first extended position by engagement with thefirst guide groove 913. Thus, during this forward movement, the cannulaholder does not move relative to the needle holder.

In this position the needle holder cannot be moved further forward, andas the spring actuator arm continues to turn clockwise it engages theguide member arranged on the lower surface of the cannula holder (notshown, see FIG. 24) thereby starting to move the cannula holder to theleft, sliding on the needle holder. At this position the guide memberhas reached the lower end of the first guide groove (see FIG. 22) and isnow moved into the second inclined guide groove where it is movedupwards along the guide groove, thereby being moved further to the left.As the cannula holder is attached to the needle holder, the needleholder is also moved upwards, however, it is guided linearly backwardsdue to the engagement with the guide member 921. When the cannula holderhas reached the upper end of the second guide groove, it has reached itssecond extended position just as the needle holder has reached itssecond retracted position (the first and second retracted positions maybe the same), just as the cannula holder has reached its second extendedposition.

As described above, the cannula has a distal portion initially arrangedwithin the needle, an intermediate portion arranged in the channelformed between the cannula and needle holder, and a proximal portionserving as a flexible connection between the moving inserter and thefluid inlet port. As the cannula is attached to the cannula holdercorresponding to the proximal end of the intermediate portion, movementto the left of the cannula holder will push the cannula through thechannel, around the bend connecting the channel and the needle, and downinto the needle. Thus as the cannula holder is moved from its first toits second extended position, the cannula is pushed out through theneedle, whereas in the meantime the needle holder with the needle isretracted (see FIG. 23C). In case the cannula and needle are extendedrespectively retracted at the same speed (this corresponding to thesecond guide groove being straight and arranged at an angle of 45degrees relative to the first guide groove) then the distal portion ofthe extended cannula will not move relative to the housing, whereas theneedle will be retracted.

In order to allow the guide member of the cannula holder to properlyenter the second guide groove, it may be desirable to connect the twoguide grooves with a short groove portion, this providing that thecannula will be extended a little before the needle starts to retract,this as shown in FIG. 23D. Correspondingly, by modifying theconfiguration of the second guide groove it is possible to retract thecannula a little from its most extended position. The latter may bedesirable in order to free a distal cannula opening from any tissue plugformed during insertion.

In FIG. 24 is shown an exploded view of the inserter seen from below,i.e. the needle holder 930 and the cannula holder 940. In the figure theflexible arm 946 for holding the cannula in engagement with the firstgripping member 941 can be seen, just as the guide member 945 arrangedon the lower surface of the cannula holder can be seen. The needleholder is provided with a longitudinal wall portion 935 adapted forengagement with the spring actuator arm. Between the two holders achannel is formed in which the intermediate portion of the cannulainitially is arranged.

In FIGS. 25A-25C are shown the relationship between the needle holder,the cannula holder, and the spring corresponding to the states shown inFIGS. 23A-23C. The partial assembly is rotated 180 degrees correspondingto the needle axis, and is thus seen from below.

In the initial position the actuator arm 961 is hold in its pre-stressedposition in locking engagement with the needle holder (see FIG. 25A).When the spring is released the actuator arm start to turn counterclockwise (as seen in the figure) whereby it engages the wall portion935 and start to move the needle holder 930 forwards to its extendedposition (see FIG. 25B). As appears, the curved distal end 962 of theactuator arm allows the arm to slide on the wall. From this position theactuator arm continuous to turn counter clockwise and subsequentlyengages the guide member 945 on the cannula holder 940 which is thenmoved to the right (as seen in the figure) to its second extendedposition and up, guided by the second guide groove, thereby moving theneedle holder to its second retracted position (see FIG. 25C). Asappears, during the latter movement the guide member 945 slides on theactuator arm. As also appears, during movement of the cannula holder,the free proximal portion 953 of the flexible cannula provides fluidcommunication between the remaining part of the cannula and the fluidport.

In the above described embodiment, a cannula is guided within a hollowneedle, however, other arrangements may be used. For example, the needlemay be part-circular (i.e. more than 180 degrees), this providing asmaller cross-sectional area during insertion. Alternatively, the needleand the cannula may be arranged side-by-side with corresponding grippingmeans provided there between providing that the cannula and needle areonly allowed to move longitudinally relative to each other.

In traditional infusion sets a pointed needle is arranged inside a softcannula, however, although the needle provides the cutting and columnarstrength during insertion, the cannula is arranged unprotected againstcompressive forces in its longitudinal direction, such forces tending tocollapse the cannula. Correspondingly, a typical infusion set cannulathus has a relatively thick wall with an outer diameter of 0.7 mm and aninner diameter of 0.4 mm. In contrast, by arranging the soft cannulainside the needle (which is typically made from medial grade stainlesssteel and thus very rigid), the properties of the needle material canused to provide a much more thin-walled outer tubular structure. Forexample, a needle with an outer diameter of 0.5 mm and an inner diameterof 0.35 mm may be used, this providing less pain during insertion, justas a thinner soft cannula may be more comfortable to wear. Acorresponding cannula will then have an outer diameter of close to 0.35mm and an inner diameter typically in the 0.15-0.20 mm range. Thecannula may be made from e.g. PTFE or FEP.

In the shown embodiment the cannula inserter mechanism is arranged in acannula unit to be used in combination with a specific pump coupleddirectly thereto, however, the principles of the inserter mechanism maybe used also in a conventional-type infusion set adapted to be connectedto an drug delivery pump by a length of tubing. Further, instead of aflexible hollow cannula, a flexible sensor may be introduced. Also,instead of inserting the cannula at an inclined angle relative to a skinsurface, a cannula may be inserted perpendicularly, i.e. inclined 90degrees. Correspondingly, the mechanism may also be arranged to insertthe cannula in a direction pointing away from the pump unit to which itis to be attached. In the shown embodiment the cannula is inclined 30degrees relative to horizontal, however, a preferred range is 20-45degrees. The less inclined the cannula is arranged, the longer theinserted length in the tissue may be, i.e. corresponding to theprotruding length of a transcutaneous device below a plane defined bythe mounting surface. For the shown angle of 30 degrees a length of 8 mmis selected, this providing a vertical insertion of approximately 4 mm.For vertical insertion a length of 12 mm or less is preferred for asteel needle, whereas a length of 9 mm or less is preferred for a softcannula. For a relatively “flat” insertion a length of 20 mm or less ispreferred for a soft cannula, typically less than 17 mm.

In FIG. 26A is shown an embodiment of a medical device 1000 of the typeshown in FIG. 1, comprising a cannula unit 1010 and a thereto mountablepump (or reservoir) unit 1050, however, instead of a needle insertionmechanism as shown in FIG. 7, a cannula inserter mechanism as describedwith reference to FIGS. 22-25 is used. In the shown embodiment thecannula unit comprises a housing 1015 with a shaft into which a portion1051 of the pump unit is inserted. The shaft has a lid portion 1011 withan opening 1012, the free end of the lid forming a flexible latch member1013 with a lower protrusion (not shown) adapted to engage acorresponding depression 1052 in the pump unit, whereby a snap-actioncoupling is provided when the pump unit is inserted into the shaft ofthe cannula unit. Also a vent opening 1054 can be seen. The housing 1015is provided with a pair of opposed legs 1018 and is mounted on top of aflexible sheet member 1019 with a lower adhesive surface 1020 serving asa mounting surface, the sheet member comprising an opening 1016 for thecannula 1017.

As appears, from the housing of the cannula unit extends a cannula at aninclined angle, the cannula being arranged in such a way that itsinsertion site through a skin surface can be inspected (in the figurethe full cannula can be seen), e.g. just after insertion. In the shownembodiment the opening in the lid provides improved inspectability ofthe insertion site. When the pump unit is connected to the cannula unitit fully covers and protects the cannula and the insertion site frominfluences from the outside, e.g. water, dirt and mechanical forces (seeFIG. 26B), however, as the pump unit is detachable connected to thecannula unit, it can be released (by lifting the latch member) andwithdrawn fully or partly from the cannula unit, this allowing theinsertion site to be inspected at any desired point of time. By thisarrangement a drug delivery device is provided which has atranscutaneous device, e.g. a soft cannula as shown, which is very wellprotected during normal use, however, which by fully or partlydetachment of the pump unit can be inspected as desired. Indeed, a givendevice may be formed in such a way that the insertion site can also beinspected, at least to a certain degree, during attachment of the pump,e.g. by corresponding openings or transparent areas, however, theattached pump provides a high degree of protection during useirrespective of the insertion site being fully or partly occluded forinspection during attachment of the pump.

In the shown embodiment an inclined cannula is used, however, in analternative embodiment a needle mechanism of the type shown in FIG. 7may be used if the point of insertion was moved closer to the couplingportion of the needle unit, this allowing also such a perpendicularlyinserted to be inspected by detaching the pump unit.

FIG. 27 shows an alternative configuration for the device disclosed inFIG. 21A. As the former embodiment the patch unit 101 comprises aflexible sheet 121 with a lower adhesive surface and an opening for thecannula, a patch housing 123 attached to the upper surface of the sheetand comprising an opening for the cannula, as well as a coupling in theform of two flexible arms 126 allowing a delivery device unit 102 to beattached. However, in contrast to the former embodiment the orientationof the angled cannula 171 has been reversed so that it pointsessentially in the opposite direction, i.e. towards the attacheddelivery device unit instead of away from the patch unit.Correspondingly, the opening in the flexible sheet is not peripherallybut more centrally located (as indicated with dotted lines 822′ in FIG.21A). As appears, this arrangement allows the point of insertion of thecannula through the skin to be hidden and thus protected by the attacheddelivery device during normal operation of the assembled device, yetallows the cannula insertion site to be inspected by simply detachingand reattaching the delivery device unit. Further, as the modifiedinserter is moved towards the delivery device unit this movement may beused to connect the fluid inlet of the cannula with the fluid outletfrom the delivery device unit, e.g. by means of a pointed needleconnector and a needle penetratable septum arranged on either of theunits. As appears, such a reversed arrangement may also be provided fora cannula inserter of the type disclosed with reference to FIGS. 15-18.

Indeed, the concept of a medical device comprising an angled insertablecannula which in its inserted position is covered by a detachableportion of the device can be used in combination with any type ofcannula-needle arrangement, not only the embodiments disclosed above.The assembly may also be provided as a unitary device in which anopening may be formed allowing the insertion site to be inspected duringuse.

Although it is believed that the above-disclosed medical devices can bemanufactured in a cost-effective manner, frequent changes of cannula orneedle devices, e.g. infusion sets, is one of the cost drivers and poorconvenience factors in CSII (continuous subcutaneous insulin infusion)treatment. It is today generally not recommended to wear an infusion setfor more than 2 days before changing it, but in practice pump users wearthem for a longer time—on average 3.3 days. One of the limiting factorsin wear time is that the risk of bacterial growth at the infusion siteincreases with longer wear times. The preservatives in insulin areanti-bacterial, but since they don't get in touch with the outside ofthe infusion needle they have no effect on this bacterial growth.

With a porous infusion needle or cannula having a pore size between themolecular size of the preservatives (typically small molecules likemeta-cresol and phenol) and the molecular size of insulin (rather largemolecules), some of the preservatives will move to the outside of needlewhere they can reduce bacterial growth and potentially increase the safewear time of the infusion needle. For a polymeric cannula the entiretube or portions thereof thus can advantageously be made from apolymeric material allowing the preservatives to diffuse from thecannula and into the subcutis. A cannula may also be made from a fibrousmaterial as used in micro tubes for dialysis. For a steel needle laserdrilling of micro side openings would allow preservatives together withinsulin to diffuse out in the subcutis along the needle (unless the sideopenings are made so small that they would be an effective barrier tothe insulin molecules). The porous portion of the needle may beuniformly porous or it may be adapted to cause weeping at a nonuniformflow rate along the length of the porous portion. A porous portion maye.g. be located at the portion of the needle or cannula intended tocross the skin barrier.

US 2004-0220536, which is hereby incorporated by reference, discloses asurgical needle with a porous distal portion from which a liquidinjectate will weep or ooze multidirectionally under injection pressurewhile the porous distal portion of the needle is inserted into a bodysurface. More specifically, it is disclosed how a needle or cannula canbe provided with pores from which a liquid will ooze. For example, theporous portion of the needle can be fabricated from any of a number ofdifferent “open cell” porous materials (i.e., materials in which thepores are interconnecting). For example, a distal portion can befabricated from a porous sintered metal, such as forms a non-wovenmatrix of metal fibers selected from such metals as stainless steel,tantalum, elgiloy, nitinol, and the like, and suitable combinations ofany two or more thereof. Generally, the metal fibers will have adiameter in the range from about 1.0 micrometer to about 25 micrometer.A non-woven matrix of metal fibers having these desired properties thatcan be used in manufacture of the porous distal portion of the inventionneedle is available from the Bekaeart Corporation (Marietta, Ga.), andis sold under the trademark, BEKIPOR® filter medium. A porous portion ofthe needle can also be fabricated from such porous materials as a porouspolymer, such as a porous polyimide, polyethylene, polypropylene,polytetrafluroethylene, and the like. Such porous polymers aredisclosed, for example, in U.S. Pat. No. 5,913,856, which is herebyincorporated by reference in its entirety. Alternatively, a porousceramic can be used, such as is known in the art for use in ceramicfilters and separation membranes, or a porous metal (also known as anexpanded metal) or carbon, such as is known in the art for use infilters or bone grafts. For example, Mott Corporation (Farmington,Conn.) manufactures porous metals for use in various types of filters.If the porous filter medium is flexible, a porous portion of a needlecan be fabricated by wrapping the filter medium, which is availablecommercially as a flat sheet, one or more times around an axis whilecreating a hollow central core. The porous portion of the needle canthen be fused in fluid-tight fashion (e.g. welded) to a non-poroushollow needle shaft using methods known in the art. To create a porousportion of the needle having decreasing impedance to fluid flow, aporous filter medium or metal mesh having an appropriate porositygradient can be employed in fabrication of the porous portion.Alternatively, a porous portion can be created from a non-porousmaterial (e.g., a metal) using a cutting laser and techniques known inthe art to punch pores into the needle segment (i.e. by a process oflaser etching). For example, the nonporous hollow shaft, porous portion,and point of a needle can be fabricated of metal in a single piece, forexample, from a conventional hypo tube. In this scenario, ametal-cutting laser is used to create a segment of the needle that hasappropriate porosity, for example, a porosity gradient within a portionof the needle to equalize fluid impedance along the length of the porousportion of the needle.

The direct advantage of the above principle is a reduced bacterialgrowth at the infusion site compared with standard infusion needles.This increases user convenience, since an infusion set can be wornlonger before it needs to be replaced a replacement that can be painfulespecially for soft infusion needles where a large diameter steel needleis used to guide the soft infusion needle into the skin. Since infusionsets are typically rather expensive, increased wear time willfurthermore be cost-attractive to pump users.

In the above-described embodiments a delivery device has been describedcomprising a flexible reservoir in combination with an example of anexpelling means in the form of a membrane pump. However, the reservoirand the expelling means may be of any type which would be suitable forarrangement within a skin-mountable drug delivery device. Further, asthe needle of the present invention also may be in the form of a needlesensor, the interior of the medical device may comprise sensor meansadapted to cooperate with the needle sensor.

In the following examples of expelling means suitable for use with thepresent invention will be described, however, these are merely examples,just as the disclosed arrangement of the individual components notnecessarily are suitable for direct application in the above showndelivery devices. More specifically, a pump arrangement may comprise adrug-containing cartridge forming a reservoir and having a distalclosure member allowing a needle to be connected, and a piston slidinglyarranged there within, a flexible toothed piston rod (for example asdisclosed in U.S. Pat. No. 6,302,869), an electric motor which via aworm-gear arrangement drives the piston rod to expel drug from thecartridge, the motor being controlled by control means and the energyfor the control means and the motor being provided by a battery. Thepump may be activated when the needle is inserted or by separateuser-actuatable means after the inserter has been detached form thedelivery device.

Alternatively a pump arrangement comprises a drug-containing cartridgehaving distal and proximal closure members and a piston slidinglyarranged there within, gas generating means in fluid communication withthe interior of the cartridge via conduit for driving the piston toexpel drug from the cartridge, the gas generating means being controlledby control means and the energy for the control means and the gasgeneration being provided by a battery. The pump may be activated asindicated above. A detailed disclosure of such gas generating means fora drug delivery device can be found in e.g. U.S. Pat. No. 5,858,001.

In a further alternative a pump arrangement comprises a drug-containingcartridge having distal and proximal closure members and a pistonslidingly arranged there within, an osmotic engine in fluidcommunication with the interior of the cartridge via conduit for drivingthe piston to expel drug from the cartridge. The osmotic enginecomprises a first rigid reservoir containing a salt-solution and asecond collapsible reservoir containing water, the two reservoirs beingseparated by a semi-permeable membrane. When supplied to the user, thefluid connection between the second reservoir and the membrane is closedby a user-severable membrane (e.g. a weak weld) which, when severed,will allow the osmotic process to start as water is drawn from thesecond reservoir through the membrane and into the first reservoir. Thepump may be activated as indicated above. A detailed disclosure of theosmotic drive principle can be found in e.g. U.S. Pat. No. 5,169,390.

In a yet further alternative a pump arrangement comprises adrug-containing flexible reservoir arranged within a rigid fluid-filledsecondary reservoir in fluid communication with a primary reservoirthrough a conduit comprising a flow restrictor. The primary reservoir isin the form of a cartridge with a movable piston and contains a viscousdrive fluid. A spring is arranged to act on the piston to drive fluidfrom the first to the second reservoir thereby expelling drug from theflexible reservoir when the latter is connected to an infusion needle.The flow rate will be determined by the pressure generated by the springin the drive fluid, the viscosity of the drive fluid and the flowresistance in the flow restrictor (i.e. bleeding hole principle). Thepump may be activated by straining the spring or by releasing apre-stressed spring, either when the needle is inserted or by separateuser-actuatable means after the inserter has been detached from thedelivery device. An example of this principle used for drug infusion isknown from DE 25 52 446. In an alternative configuration, the drugreservoir may be pressurized directly to expel the drug via a flowrestrictor, e.g. as disclosed in U.S. Pat. No. 6,074,369.

In FIG. 28 is shown a medical device 1900 corresponding to theembodiment of FIGS. 1-3, however, the reservoir unit has a modulardesign comprising a “durable” control unit 1910 adapted to be mounted ona reservoir unit 1920 comprising a reservoir and an expelling assemblycontrollable by the control unit through contacts 1921. Thetranscutaneous device unit 930 may e.g. be the same as in FIGS. 1-3. Thetranscutaneous device unit and the reservoir unit comprise matingcoupling means (1931) allowing the reservoir unit to be secured to thetranscutaneous device unit to provide fluid communication between thereservoir and the transcutaneous device, and the controller unit and thereservoir unit comprise mating coupling means (1917, 1921) allowing thecontroller unit to be secured to the reservoir unit to control theexpelling assembly. The control unit may comprise one or more of thefollowing features: a vibrator, a RF transmitter, a RF receiver, adisplay, a bolus button 1918 (as shown) or other user input means, aback-up battery, a memory. Further, the control unit may be adapted toprovide a fixed flow rate or it may be programmable (e.g. via a remotecontrol) to provide a given rate or a given profile. The differentcontrol units may also be used with different reservoir units (e.g.comprising different drugs or different amounts of drugs), or withdifferent needle units (e.g. comprising a needle or a soft cannula). Asstated above, the controller may be used as a durable device by theuser, however, (simpler) versions of the controller may comepre-attached to a reservoir unit and be used as a means to provide avariety of disposable devices.

FIG. 29 shows a modular system comprising a number of different types ofcontrol units in addition to a basic needle patch unit 1930 and a basicreservoir unit 1920. A remote controller 1940 may be used in combinationwith some of the control units. The control unit may be in the form of aremotely controllable unit 1911 which can only be controlled from aremote controller. A variant 1912 thereof may add a bolus buttonallowing the user to take a bolus of drug without having to use theremote controller. The control unit may be provided as a variety ofpreprogrammed control units 1913, each providing a fixed flow rate asindicated on the unit. Such a unit is intended for use without a remotecontroller and may include a display 1919 as shown. A programmablecontrol unit 1914 may also be provided, this allowing e.g. a medicalpractitioner to program the control unit for an individual patient. Adummy 1915 represents any of the disclosed control units in combinationwith a reservoir unit and a needle unit.

In the above disclosure of preferred embodiments of the presentinvention a system has been described comprising a medical device 1900used in combination with a remote controller, however, the medicaldevice of the present invention (e.g. a medical device comprising atranscutaneous unit and a reservoir unit or a sensor device comprising asensor unit and processor unit adapted to transmit and/or process dataacquired via the sensor) may also be used in combination with other andfurther components to form other systems.

For example, the medical device may be used in combination with one ormore sensing devices including a sensor adapted to be used indetermining a concentration of an analyte of the user. For the treatmentof diabetes and to assist in the controlled infusion of insulin, asensing device may be adapted to measure a blood glucose level in theuser. To determine the blood glucose level of a person suffering fromdiabetes, two types of devices may be used.

The traditional blood glucose meter (BGM) is normally used manually agiven number of times each day and is based on the application of asmall amount of blood to a test strip 1821, 1831 (see FIG. 30A) which isthen subsequently placed in the BGM which then supplies a blood glucosevalue on its display. Traditionally this value was used to check thatthe blood glucose value was within a desired range, however, it may alsobe entered into a bolus calculator (also termed a bolus estimator) whichwill then e.g. recommend a correction bolus to be injected or infused.An early example of a bolus calculator is the “B-D Insulin DosageComputer” which can also be used to calculate a meal bolus on the basisof user-entered meal information. A bolus calculator may also beincorporated into a drug delivery device, e.g. as shown in U.S. Pat.Nos. 5,665,065 and 6,554,798 or US 2004/0068230, or it may beincorporated into a remote controller for a drug delivery device asshown e.g. in US 2005/0022274 or US 2005/0065760 (also showing that aBGM may be incorporated in the remote controller), which are hereby allincorporated by reference. It is considered that the general design of aremote controller and the corresponding aspects of a controlled deviceare well known to the skilled person, however, for a more detaileddescription of the circuitry necessary to provide the desiredfunctionality of the present invention reference is made to US2003/0065308, which are hereby all incorporated by reference.

In addition to a BGM blood glucose values may also be provided using acontinuous blood glucose meter (CGM) which provides continuous orquasi-continuous (e.g. every five minute) blood glucose values. A CGMmay be implantable or non-implantable based on e.g. a transcutaneoussensor, a non-transcutaneous sensor or micro-dialysis using a smallcannula, and often comprises an external portion attached to the skin ofthe user by adhesive, the sensor and the external portion forming asensor unit. The external portion comprises sensor electronics adaptedto process and/or transmit the “raw” sensor data supplied from thesensor being indicative of the determined concentration of the analytein the user. For example, the sensor data may be transmitted to afurther unit by wire or wirelessly for further processing, or they maybe processed in the external portion of the sensor unit to determine aconcentration of the analyte (e.g. glucose) in the user. These valuesmay then be displayed by the sensor unit and/or transmitted to a furtherunit by wire or wirelessly, where it can be displayed, stored and/orused for further processing. The values supplied from or via the CGM maybe used by a bolus estimator for calculating an estimated amount of drug(e.g. insulin) to be infused into the body of the user based upon thereceived data or they may be used in a closed-loop system for adjustinga basal rate infusion of a drug. Preferably, also BGM values aresupplied to the bolus estimator or system in order to adjust for anysensor drift. The bolus or closed-loop calculator may be part of a drugdelivery device or it may be part of a remote control unit from whichcommands are then transmitted to the delivery device. In the followingand with reference to FIGS. 30A-30C a number of exemplary systems 1800,1801, 1802 will be described using one or more sensor devices fordetermining blood glucose, however, other types of sensors fordetermining the concentration of other analytes may be used. In thebelow examples the remote control unit is used to collect BGM/CGM dataand to calculate and transmit bolus instructions to the delivery device,however, the remote control unit is preferably used as the main userinterface between the delivery device and the user allowing the user toe.g. program the delivery device with a given basal rate profile and tochange such a profile, to program a bolus amount and the form thereof,and receive information from the delivery device (e.g. by detection ofan occlusion). The remote unit may also serve as a storage device forstoring information in respect of infusion history (e.g. basal rate andbolus infusions), alarms, personal information (e.g. for preferred typesof meals to be used in bolus calculations) and to send data to anexternal device such as a PC or expert system.

EXAMPLE 1

A medical drug delivery device 1810 comprising a transcutaneous deviceunit 1811 and a reservoir unit 1812 as disclosed above is provided incombination with a BGM 1820 and a wireless remote control unit 1830comprising a processor and an infusion calculator, thereby formingsystem 1800. On basis of blood glucose values and/or values entered intothe system by a user via a keyboard 1831 (e.g. in respect of a meal) abolus is calculated and when accepted by the user it is transmitted tothe drug delivery device which then infuses the bolus. The BGM data maybe entered into the remote unit manually, they may be transmitted fromthe BGM to the remote unit or the BGM may alternatively be integratedinto the remote unit. The CGM shown in FIG. 30A is not used in thissystem.

EXAMPLE 2

A medical drug delivery device 1810 comprising a transcutaneous deviceunit and a reservoir unit as disclosed above is provided in combinationwith a BGM 1820, a CGM 1840 and a wireless remote control unit 1830comprising a processor and an infusion calculator, thereby formingsystem 1800. Data is transmitted from the CGM to the remote unit wherethey are used in conjunction with BGM data and optionally other data tocalculate a bolus or a change in an actual basal rate infusion profile.When a bolus or profile change is calculated it may be transmittedautomatically to the drug delivery device (closed loop) or it may bedisplayed to the user for acceptance (open loop). The BGM data may beentered into the remote unit manually, they may be transmitted from theBGM to the remote unit or the BGM may be integrated into the remoteunit. The data supplied from the CGM and BGM may be raw sensor data orprocessed data representing a blood glucose value.

EXAMPLE 3

A medical drug delivery device 1810 comprising a transcutaneous deviceunit and a reservoir unit as disclosed above is provided in combinationwith a BGM 1820, a CGM 1840 and a wireless remote control unit 1830comprising a processor and an infusion calculator, thereby formingsystem 1801. Data is transmitted from the CGM to the delivery device andfrom the delivery device to the remote unit. This arrangement may beadvantageous when the distance between the sensor unit and the deliverydevice is small and when the delivery device is provided with a memory,this allowing CGM data to be transmitted to the remote unit “in bulk”,e.g. every hour, this improving energy efficiency. Otherwise the systemmay be provided and used as described in example 2.

EXAMPLE 4

A medical drug delivery device 1815 comprising a transcutaneous deviceunit and a reservoir unit as disclosed above is provided in combinationwith a BGM 1820, a CGM 1816 and a wireless remote control unit 1830comprising an infusion calculator, thereby forming system 1802. Incontrast to examples 2 and 3, the CGM is formed integrally with thedelivery device. Advantageously a transcutaneous sensor 1817 is formedas part of the transcutaneous device unit and the sensor electronicsadapted to process and/or transmit the sensor data is formed as part ofthe reservoir unit. The sensor may be replaced together with thetranscutaneous device or independently thereof. Otherwise the system maybe provided and used as described in example 3.

EXAMPLE 5

A medical drug delivery device comprising a transcutaneous device unitand a reservoir unit as disclosed above is provided in combination witha BGM and/or a CGM, the reservoir unit being adapted to receive BGM/CGMdata (e.g. wirelessly) and comprising a bolus calculator. The boluscalculator may use the BGM/CGM to calculate a recommendation asdescribed above in examples 1 or 2, or it may calculate and implement abolus or change of infusion profile.

In the above examples, when a separate medical sensor device is used(e.g. a CGM sensor), such a sensor device may comprise a sensor unit anda processor unit, the sensor unit comprising: a transcutaneous sensordevice, a mounting surface adapted for application to the skin of thesubject, the processor unit comprising: a processor adapted to transmitand/or process data acquired via the sensor, wherein the sensor unit andthe processor unit are adapted to be secured to each other in asituation of use to thereby form a unitary device. Turning to FIGS. 31Aand 31B a sensor unit 1850 is shown, comprising a transcutaneous device1851 in the form of a needle-formed sensor 1852 in combination with aninsertion needle 1853, and a mounting surface 1855 adapted forapplication to the skin of the subject. After the sensor unit has beenplaced on a skin surface (see FIG. 31A) the combined transcutaneousdevice is inserted transcutaneously by the user where after theinsertion needle is withdrawn, this leaving the sensor in place (seeFIG. 31B. Finally the user attaches the process unit 1860 therebyestablishing contact between the needle sensor and the circuitry of theprocess unit. The process unit comprises a processor 1861 adapted totransmit and/or process data acquired via the sensor device as well as apower source 1862. A further example of sensor insertion can be found inU.S. Pat. Nos. 5,568,806 and 6,809,653, which are hereby incorporated byreference, also disclosing technical information in respect ofcommunication between a medical sensor and an external device.

In the above description of the preferred embodiments, the differentstructures and means providing the described functionality for thedifferent components have been described to a degree to which theconcept of the present invention will be apparent to the skilled reader.The detailed construction and specification for the different componentsare considered the object of a normal design procedure performed by theskilled person along the lines set out in the present specification.

1. A medical device, comprising a transcutaneous device unit and aprocess unit, a) the transcutaneous device unit comprising: a mountingsurface adapted for application to the skin of a subject, and atranscutaneous device comprising a distal end adapted to be insertedthrough the skin of a subject, the distal end being movable between aninitial position in which the distal end is retracted relative to themounting surface, and an extended position in which the distal endprojects relative to the mounting surface, b) the process unitcomprising: a process assembly adapted to cooperate with thetranscutaneous device, wherein: the transcutaneous device unit and theprocess unit are adapted to be secured to each other to form a unitarydevice, the transcutaneous device unit comprises a removable inserterportion, and the inserter portion has to be removed prior to securingthe process unit.
 2. A medical device as in claim 1, wherein: thetranscutaneous device unit comprises a patch unit comprising themounting surface, and the removable inserter portion initially comprisesthe transcutaneous device, the inserter portion being adapted to beremoved from the patch unit after the transcutaneous device has beeninserted through the skin of the subject.
 3. A medical device as inclaim 1, wherein the transcutaneous device is provided in combinationwith a pointed insertion needle being retractable relative to thetranscutaneous device.
 4. A medical device as in claim 1, wherein thetranscutaneous device unit comprises actuation means for moving thedistal end of the transcutaneous device between the initial and theextended position when the actuation means is actuated.
 5. A medicaldevice as in claim 1, wherein the transcutaneous device is in the formof a transcutaneous sensor device, and the process assembly comprises aprocessor adapted to transmit and/or process data acquired via thesensor device.
 6. A medical device as in claim 1, wherein thetranscutaneous device is in the form of a transcutaneous access device,and the process assembly comprises a reservoir adapted to contain afluid drug, an expelling assembly adapted for cooperation with thereservoir to expel fluid drug out of the reservoir and through the skinof the subject via the transcutaneous access device, and a processor forcontrolling the expelling assembly.
 7. A medical device as in claim 1,wherein the process unit is adapted to be releasably coupled to thetranscutaneous device unit thereby, in a situation of use, substantiallycovering an introduction site of the transcutaneous device through theskin, and wherein at least partial removal of the process unit from thetranscutaneous device unit at least partially uncovers the introductionsite.
 8. A medical device as in claim 1, the transcutaneous device unitcomprising a housing portion to which the transcutaneous device ismounted when inserted, and a flexible sheet member provided with anadhesive layer on its lower surface, this allowing the transcutaneousdevice unit to be attached to the skin of the subject.
 9. A systemcomprising: a medical device as in claim 1, and a remote control unitcomprising a processor, the medical device and the remote control unitbeing adapted to transmit data there between.